An On Board Charge Module (OBCM) refers to a power conversion apparatus mounted in an electric vehicle and charging an on board battery pack through a ground AC grid. During charging, a user can charge the electric vehicle by directly inserting an AC power cable into a socket of the electric vehicle. Such power conversion apparatus at least include a power conversion module, a base housing, and the like. The power conversion module is used to convert an external power supply into an AC or DC power supply for various voltage levels used in the vehicle. When the power conversion module is operating, a large amount of heat is generated. The base housing provides a heat-dissipation design to dissipate the heat generated by the power conversion module, so as to avoid the accumulation of heat affecting the overall performance of the power conversion module. At present, however, the design of the power conversion module and the heat dissipation design correspondingly provided by the base housing are not good, resulting in a large overall volume of the on board charge module and a low power density.
Therefore, one problem in the field that needs to be settled urgently is how to develop a power conversion apparatus to solve the problems in the prior art.